Implantable Devices to treat specific conditions
(c) 2026 David Prutchi PhD
In his early days, Wilson Greatbatch used to prototype his pacemaker circuits onto a manila folder printed with the circuit’s schematic.
In 2000 he gave this reproduction of his 1961 pacemaker to the North American Society of Pacing and Electrophysiology (NASPE, now the Heart Rhythm Society -HRS). Continue reading
(c)2026 David Prutchi PhD
While documenting lesser-known implantable devices, I recently came across a pacemaker from a company that has largely vanished from the historical record: American Tech, Inc., based in Northridge, California.
American Tech, Inc. was a short-lived U.S. pacemaker manufacturer based in Northridge, California, active in the mid/late 1970s, that appears to have focused on the development of very small, compact implantable pacemakers for its time. Although the company has largely disappeared from the historical record, surviving devices such as the DU-15 pacemaker illustrate an early attempt to minimize implant size during a period of rapid technological change in cardiac pacing.
Contemporary regulatory summaries and Senate staff reports indicate that the company marketed several models under the DU-series and related product families. At least one clinical evaluation of the DU-15 was underway by the end of the decade, suggesting that implants were occurring by approximately 1978–1979.
Like several other small pacemaker manufacturers of that era, American Tech faced significant challenges. FDA advisories issued around 1979–1980 cited reliability concerns affecting multiple products from the company. By 1980, American Tech had withdrawn from the U.S. pacemaker market, and there is no evidence that its pacemaker business, or the company itself, was acquired by another manufacturer. Unlike some contemporaries, no successor firm assumed service or warranty responsibilities, suggesting that American Tech simply ceased operations.
American Tech, Inc. represents one of many small pacemaker manufacturers that briefly emerged during the late 1970s and disappeared as cardiac pacing technology matured and the industry consolidated. Its emphasis on miniaturization foreshadowed a design priority that would later become central to implantable pulse generator development.
(c) David Prutchi PhD
While helping triage HRS’ collection of implantable devices, I was surprised to find a pacemaker by an Argentinian company about which I hadn’t heard before.
The mercury-cell-powered pacemaker shown in the picture was made by Marcapasos Argentinos, a company that was based in Córdoba, Argentina. From what I’ve been able to find, the company was founded by Dr. Jorge Raúl Ruiz Aguilar (1927 – 1997) and engineer Eduardo Tagle to develop and manufacture demand pacemakers domestically.
There is very little information that I was able to find online about the company or the device. Eduardo Tagle’s LinkedIn states that over 3000 IPGs were implanted, and a short blurb about Dr. Ruiz Aguilar in the Argentinian Journal of Cardiovascular Surgery (Uribe A. Primera época de la cirugía cardíaca en Córdoba. Bosquejo histórico. Revista Argentina de Cirugía Cardiovascular (RACCV). 2009;VII(3):236–242.) says that the company was acquired by one of the large cardiac rhythm management companies of the time.
One additional breadcrumb: a publicly posted CV from Córdoba lists employment at Marcapasos Argentinos SRL (1975–1976) as an ‘operario de armado de plaquetas’ (PCB assembly operator), consistent with in-house electronics manufacturing.
If you know any other details about them, please contact me!
(c) 2026 David Prutchi PhD
The Medtronic 5998 was a patient-activated implant used in the 1980s to manage tachyarrhythmias. The device was implanted to allow patients to trigger overdrive atrial pacing via a handheld transmitter to revert paroxysmal supraventricular tachycardia (PSVT).
The 5998R receiver was connected to a Medtronic 6991 right atrial lead. When the patient activated the 5998TDA transmitter, a burst of pacing was delivered to the heart. Brief periods (5 to 20 seconds) of rapid atrial pacing were effective in terminating the SVT and returning the heart to normal sinus rhythm. Documented issues with the device included inconsistent reversal of arrhythmias, and potential for transient atrial fibrillation.
The Medtronic 5998 RF system was in clinical use and described in the literature from at least 1981 through at least 1988.
(c)2026 David Prutchi PhD
In the 1960s and early 1970s, pacemakers powered by mercury/zinc cells had to be enclosed in epoxy because the cells produced hydrogen, which could safely diffuse outward through the epoxy’s permeability to hydrogen.
However, epoxy encapsulation also allowed water molecules to penetrate into the battery area and electronic assembly, often causing their failure.
In 1971, Australian pacemaker company Telectronics produced the model P8; the first hermetically sealed pulse generator in a titanium case. The hydrogen problem was taken care of by means of a
hydrogen absorbent inside the case, and the high welding temperature needed to seal the case, without damaging the contents, by a carefully worked out combination of fast welding and external heat sinking and cooling.
The P10 model shown here was based on the P8, but incorporated a silicone elastomer coating to limit the area of the indifferent electrode to prevent pectoral muscle stimulation.
(c) 2026 David Prutchi and Daniel Villamil. All rights reserved
I’m pleased to share that our paper is now available online in PACE: “Pioneering Rhythm Management: A Design Analysis of the Earliest Battery-Powered Implantable Pacemakers.”
Over the past year, my colleague Daniel Villamil and I have pursued this as a hobby project, combining historical research with hands-on engineering. We analyze the earliest battery-powered implantable pacemakers developed independently by Rune Elmqvist (1958) and Wilson Greatbatch (1960), and we reconstruct faithful working replicas to explore the design tradeoffs and constraints that shaped these devices.
The print version will be published soon. The online version is here: http://doi.org/10.1111/pace.70127 (note: the article is not open access).
Image Credit: Coherence Neuro
Coherence Neuro was originally incorporated as Opto Biosystems Ltd in in Cambridge, UK on March 17, 2022 by Drs. Ben Woodington and Elise Jenkins. It describes itself as a medical technology company developing implantable neurotechnology that can record electrical activity and deliver targeted electrical modulation as a new bioelectronic approach to cancer care. Their flagship system is SOMA-1, presented as an MRI-compatible, minimally invasive brain–computer interface intended to be implanted during existing neurosurgery to monitor and treat gliomas in real time.
A Neurofounders article, described how Coherence wants to measure neural activity patterns, specifically the rate and structure of neuronal firing, and use those signals to infer how the tumor is interacting with surrounding neural circuits and how it is changing over time. The stated clinical vision is that continuous sensing could provide clinicians with higher-temporal-resolution information about progression and response than current workflows, which often depend on scans spaced months apart.
The same piece lays out three therapeutic “lanes” for stimulation:
Coherence Neuro believes that the same concepts could be applied to cancer in other parts of the body, and they mention in their website that they have started to investigate the use of SOMA in pancreatic cancer.
Their published patent application is understandably high level, and it does not clearly identify the specific neural biomarker they plan to track or the stimulation patterns they believe will meaningfully disrupt tumor progression. I am interested to see how this translates in practice, but I will look to controlled clinical data before drawing conclusions.
Image Credit: Valencia Technologies
On March 1, 2022 FDA approved Valencia Technologies’ eCoin Peripheral Neurostimulator System to stimulate the tibial nerve to treat Urge Urinary Incontinence. The eCoin system delivers electrical pulses to the tibial nerve in 30-minute sessions based on a fixed schedule. A healthcare provider can adjust the level of stimulation based on each patient’s sensitivity and needs, using the remote control.
Boston Scientific today announced it has entered into a definitive agreement to acquire Valencia Technologies Corporation. Terms of the acquisition have not been disclosed.
Image Credit: Biotronik
In 2023 Biotronik received FDA approval for its Prospera™ Spinal Cord Stimulation System to treat chronic, intractable pain. The system features connectivity with Biotronik’s Embrace One™, which the company claims to provide automatic, objective, remote daily data transmission for true proactive care management.
A new study using the Prospera® SCS system was published in Neuromodulation supporting the adoption of real-time remote monitoring as a new standard for long-term SCS device management.
According to the press release, the study demonstrates that:
“…automatic, daily remote monitoring of spinal cord stimulation (SCS) devices enables the first real-time visibility into post-implant therapy use, including the identification of “virtual explants” — patients with prolonged device inactivity who have not undergone surgical removal. In the study, patients using the Prospera® SCS system — the only SCS device with automatic, objective, daily remote monitoring and remote programing — maintained high rates of therapy use and low explant rates.”
Dr. Shmuel Yerushalmi ז״ל (1934–2025)
Pacemaker Pioneer and Builder of Israel’s Biomedical Industry
I was deeply saddened to learn of the passing of Dr. Shmuel Yerushalmi ז״ל, a pacemaker pioneer whose work has been central to my research on the early history of implantable cardiac devices in Israel, and whom I had planned to visit during my current stay in the country.
Dr. Yerushalmi’s death marks the loss of one of the key figures in the formative period of Israel’s implantable medical device industry. He was an engineer whose career bridged academic research, industrial development, and the practical challenges of bringing life-sustaining technology to patients. Continue reading
Coratomic, Inc. was a cardiac device manufacturer based in Indiana, Pennsylvania. It was one of a handful of American firms that developed and marketed plutonium-238 radioisotope-powered pacemakers in the 1970s. Coratomic grew out of the Allegheny General Hospital nuclear-pacemaker program led by George J. Magovern, Sr., with David L. Purdy as the key technical founder and executive, and Nicholas P. D. Smyth as a principal clinical collaborator.
The initial enthusiasm for Pu-238 pacemakers waned as regulatory complexity, public concern about implanted nuclear material, and the improving longevity of lithium-chemistry cells converged. Like the other pacemaker companies of the time, Coratomic abandoned the development of radioisotope-powered devices and concentrated on lithium-powered pacemakers.
A few months ago, I was contacted by Tim Vore, a resident of Indiana, Pennsylvania, where Coratomic pacemakers were manufactured. He had found a few demo models at an estate sale, tucked inside an old, beaten-up desk in an attic. I acquired these from him (with his permission to tell the story of where he had found them).
Upon receiving them, I x-rayed the units and confirmed that they are all weighted mechanical dummies, except for one of the Ovalith units in which half of the shell had been cut open and the pacemaker’s internals were encapsulated to display their microcircuit (still using miniature, albeit discrete, components) and battery. The collection also included a few setscrew wrenches and hybrids encapsulated in dual-in-line metallic chip carriers.
In 1986, Coratomic changed its name to Biocontrol Technology, Inc., exited the pacemaker business, and focused increasingly on other medical technologies, notably a non-invasive glucose monitor.
A 2002 Pittsburgh Tribune-Review article states that “Bico, formerly known as Biocontrol Technology Inc., and before that, Coratomic Inc.” had accumulated large losses. Not surprisingly, in March 2003 Bico Inc. filed for Chapter 11 bankruptcy protection in federal court in Pittsburgh. As part of its court-approved reorganization, it later merged with cXc Services, Inc. – a small, privately held Delaware start-up created in 2003 to commercialize a “WebPhone” videophone product – marking a complete departure from its origins in implantable cardiac devices.
Image Credit: Impulse Dynamics
Impulse Dynamics, the company where I serve as Executive VP and CTO announced that the Centers for Medicare and Medicaid Services issued yesterday a favorable National Coverage Decision (NCD) memo for Cardiac Contractility Modulation (CCM®) Therapy. The decision was supported by the American College of Cardiology, the Heart Failure Society of America, and the Heart Rhythm Society.
According to the announcement:
“CCM® therapy for heart failure (HF) patients is one of only five therapies selected for the Transitional Coverage for Emerging Technologies (TCET) pathway in 2025. This determination marks a transformative milestone for HF patients and their providers, validating that CCM® therapy is no longer experimental or investigational.”
Image Credit: Nalu
Nalu Medical, Inc. is a privately held, early-stage start-up based in Carlsbad, California. They developed the Nalu micro-Implantable Pulse Generator (mIPG) system, which consists of a fully-featured, battery-free, miniaturized IPG, which is powered by an externally worn Therapy Disc and controlled through a smartphone based remote control app. The Nalu Neurostimulation System is currently FDA-cleared for Spinal Cord Stimulation (SCS) and Peripheral Nerve Stimulation (PNS) indications.
On October 17 Boston Scientific announced it has entered into a definitive agreement to acquire Nalu Medical, Inc. for an upfront cash payment of approximately $533 million for the remaining equity not owned by Boston Scientific (which has been a strategic investor since 2017).
Image credit: Medtronic
On September 19, 2025, Medtronic announced that it had received FDA approval for its Altaviva implantable tibial nerve neurostimulator for the treatment of urge urinary incontinence (UUI). The device is inserted near the ankle during a minimally invasive procedure that doesn’t require sedation or imaging, and is then activated to deliver therapy automatically.
The device is powered by a rechargeable battery based on Medtronic’s proprietary Overdrive™ battery technology with an expected longevity of 15 years. According to Medtronic, the Altaviva IPG only needs to be recharged 1–2 times per year under standard therapy settings, with each session taking about 30 minutes when properly positioned.
Image Credit: MicroCHIPS, Inc.
Daré Bioscience is a female-health-focused biotech company conducting end-to-end clinical development in ob-gyn. They are developing the “DARE-LARC1” smart implant, a programmable drug delivery system for long-acting reversible contraception (LARC) and other long-term therapeutic uses like diabetes and obesity. This implant uses programmable micro-reservoirs to deliver precise doses for months to years from a single device, features wireless control with smartphone integration, can have its software updated remotely, and is powered by a battery designed to last up to 20 years. According to the company:
“DARE-LARC1 is a preclinical-stage investigational, long-acting reversible contraceptive (LARC) utilizing a next-generation programmable drug delivery device to administer levonorgestrel, the active pharmaceutical ingredient in a number of FDA-approved birth control methods, for an extended period without requiring day-to-day effort.”
Daré announced that it had received a $4.0 million non-dilutive funding installment under its multi-year grant agreement to support development of DARE-LARC1. This brings the total received to approximately $41.8 million of the up to approximately $49 million in committed grant funding for nonclinical development, IND-enabling studies, and preparation for submission of an Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA).